The present invention relates to a contact lens holder for use in measurement of the power of contact lenses.
For measuring the power of a contact lens, particularly a hard contact lens, the lens is placed on a lens support in an optical measurement machine known as a lens meter, and is adjusted in position to bring the center of the contact lens into alignment with the optical axis of the lens meter. Since contact lenses are quite small in size, however, it is tedious and time-consuming to set a contact lens in a desired position on the lens support.
It has been customary to hold the contact lens down against the lens support by hand during the process of measurement, or to place the contact lens on the lens support and allow the lens to be positioned by gravity. The manual attempt to keep the lens in place has been disadvantageous in that the contact lens is too small to be handled by hand for neat installation on the support, resulting in an erroneous measurement of the power of the contact lens, and the contact lens to undergo warpage under undue forces applied, with the consequence that the measurement image of the contact lens will be distorted. One of the operator's hand is fully occupied to hold the contact lens, and hence is not available for other operations throughout measurement. The gravity-supported contact lens is apt to drop easily off the lens support when subjected to small shocks or vibrations or even weak air streams. The lens support is required to be maintained horizontally at all times, a procedure which has made measuring processes highly complex.